The invention relates to sealing and insulating devices, and more particularly to methods of installing sealing and insulating devices in a space which is no larger in transverse dimension than the thickness of the insulation device.
The present invention has numerous practical applications for sealing and insulating between spaced apart surfaces. For example, when insulating the space between spaced apart surfaces, it is often desirable to have the insulation completely fill the transverse distance between the two surfaces thereby avoiding voids between the insulation and surfaces. It is however, difficult to install insulation within a space which is no larger in transverse dimension than the thickness dimension of the insulation which is to be installed therein.
As another example, to insulate a space between spaced apart surfaces, it is desirable to use a foam insulation material. Typically, the foam insulation material is injected in liquid form into the space between the surfaces, and allowed to foam in situ to fill the space. It is however, difficult to seal the space to confine the foaming insulation material and prevent the foaming insulation material from leaking out of the space to be insulated.
The invention finds particular utility in insulating and sealing between prefabricated panels with spaced apart sides, and which are compact in physical size with relatively small spaces therebetween to be insulated. For example, the invention can be used in the insulation of automobile components such as doors or trunk lids and construction products such as windows and doors, and home appliances such as refrigerators, water heaters and dishwashers.
As one example, U.S. Pat. No. 4,399,645 issued Aug. 23, 1983 to Murphy et al. describes a bladder which may be installed in the side wall of a structure, such as between studs, and inflated after being installed. By inflating the otherwise collapsed bladder, it is forced into contact with the enclosing walls or sides of the structure space and may thereafter be filled with insulation. Also disclosed is the use of adhesive to securely bond the bladder to the defining walls (sides) of the space where it is installed. Removal of the air within the insulation-filled bladder is accomplished by injecting a gaseous medium such as carbon dioxide. Instead of using pressure in the bladder, a vacuum may be utilized. This reference also mentions concerns over off-gas generation. In contrast, the present invention draws a vacuum on the envelope after it is filled with insulation so as to resiliently compress it and its contents to a significantly smaller size for installation. The vacuum is released after installation where in Murphy the vacuum is applied after installation. The present invention necessitates resilient, flexible materials for both the envelope and the filler insulation while Murphy does not.
As another example, the typical water heater device is constructed of an inner water tank with an outer shell located concentrically over the inner tank and defining an annular space therebetween. A cap closes the top end and a floor closes the bottom end of the water heater device. The annular space between the inner tank and outer shell is filled with a thermal insulation. For many years fiberglass mats or batts have been used as the insulation material between the inner tank and outer shell. Preferably, these mats should be of a thickness or radial width at least equal to the radial width of the space between the inner tank and the outer shell to provide optimum insulation results. However, this desired fit presents a problem when assembling the outer shell concentrically over the inner tank because the mat then physically interferes with the movement of the outer shell over the inner tank.
More recently a foam such as urethane, has been used as the thermal insulation material in place of fiberglass between the inner tank and outer shell. Typically a foam material is injected into the annular space between the inner tank and outer shell, and is allowed to foam in situ. However, there is a problem in restraining the expanding foam within the annular space and more particularly within a predetermined location or region within the annular space.
The following U.S. Patents illustrate various prior art attempts to insulate water heaters.
U.S. Pat. No. 4,372,028 issued on Feb. 8, 1983 to Clark et al. shows a water heater having a foam-filled closed bag (collar) located in the annular space between the inner tank and outer shell at the bottom of the inner tank, with the annular space above the annular bag filled with expanded foam. The collar functions as a stop to the expanded foam in the annular space thereabove. In the manufacture of the water heater a flexible, expandable closed elongated bag having a hole therein is filled with a foam material which expands the bag, and before the foam material has had sufficient time to fully expand, the bag opening is sealed and the bag is circumferentially wrapped around the lower end of the tank with the bag ends overlapping each other. Then, still before the foam material in the bag has had sufficient time to expand, the outer shell is positioned over the inner tank and bag. The foam in the bag expands to be in compression between the inner tank and outer shell. The annular space above the collar is then filled with expandable foam material.
U.S. Pat. No. 4,447,377 issued on May 8, 1977 to Denton shows a gas fired water heater wherein a layer of fiberglass batt insulation material is wrapped around the bottom portion of the inner water tank around the combustion chamber and a plastic envelope is wrapped around the inner tank above the fiberglass insulation. The envelope is in the form of an elongated thin tube having an inner wall, an outer wall, a bottom wall, two end walls and an open top. When wrapped around the inner tank, the end walls of the envelope abut each other. The outer shell is positioned over the inner tank such that the envelope is in the annular space therebetween. Expandable foam is injected through the open envelope top into the envelope and allowed to expand therein. The fiberglass batt does not form a seal between itself and the inner water tank and the outer shell.
U.S. Pat. No. 4,477,399 issued on Oct. 16, 1984 to Tilton shows a water heater having an inflatable toroidally shaped tube located around the bottom end of the inner tank such that when the toroidal tube is inflated with air, it seals the bottom end of the annular space between the inner tank and outer shell. A foamable material is then injected into the annular space above the toroidal tube to fill the annular space.
U.S. Pat. No. 4,749,532 issued June 7, 1988 to Pfeffer discloses a method of wedging a band of insulation around the tank as a barrier to liquid foam. The arrangement uses a "shoe horn" to compress inwardly the outer edges of the fiberglass belt so that the shell can be lowered into position without interference.
Each of the above discussed known water heater constructions present numerous problems in manufacture such as, for example, a large number of steps, critically timed steps, and time consuming steps which add to the cost and present potentials for defects in the final product.
U.S. Pat. No. 4,736,509 issued Apr. 12, 1988 to Nelson discloses a method of sealing the lower portion of the annular space between the tank and shell. This arrangement offers a number of improvements to water heater construction since a sealing cuff is somewhat "automatically" formed as the shell is lowered into position. There are a number of time and quality benefits, but the concept is generally limited to water heaters.
As a further example of an application for the present invention, home automatic dishwashing machines are typically installed in a confined space in kitchen cabinetwork beneath the counter top. In order to reduce noise transmission generated by the mechanism of the dishwasher machine it would be advantageous to install an acoustical insulation between the dishwasher and cabinetwork. This insulation should totally fill the space between the dishwasher and the cabinet to seal what would otherwise be a direct transmission path to the kitchen environment. However, the space between the dishwasher machine and cabinetwork is so tight that to date it is a virtual impossibility to do so.